function mat=priorbeta(alpha,step,min,max); 
%function mat=priorbeta(alpha,step,min,max) 
% Provides means and SD for a Beta 
%   distribution with alpha 
%   step defines increments 
%   min and max the bounds for beta 
beta=(min:step:max)';
lvec=length(beta); 
alpha=repmat(alpha,lvec,1); 
m1=alpha+beta; 
meanm=alpha./m1; 
den=(m1.^2).*(m1+1); 
varm=(alpha.*beta)./den; 
mat=[beta meanm sqrt(varm)]; 
